Sphygmograph



Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE ANDREAN G. RONNING,

OF MINNEAPOLIS, MINNESOTA; J'AOOB A. BONNING .AN'D

SPHYGMOGBAPH Application filed July 29,

. This invention relates to devices known as sphygmographs or sphygmometers for permanently recording the variables and characteristics of human (or animal) heart beats, and the primary object is to provide means, of a simple, efiicient and practical nature, for graphically indicating the heart beats in such a manner that a completeand accurate record of the frequenc strength, regularity and consistency of the cart action may be obtained. The value of such a record is obvious, as it enables the erson or a physician to carefully and deli erately examine the heart action at such times as may be convenient, and permits a closer and more valuable observation of the heart than is obtainable, for instance, by merely timing the pulse, to a watch, a practice which is not only unreliable and inaccurate, but at its bestbing dicates nothing more than the heart frequency. The present device, however, will not only ositively and accurately re ter the pulse requency, 1. e., the number of eats per minute, but will also indicate the stren h of thebeat, i. e., the force of the blood ow causing the arterial throbbing, and will also chart the regularity or consistency of the creased out. The present device,

pulse so as to show whether or not the heart functions the same continually or if it is sub ject to variable periods of increased and deactivity. Some of these characteristics can be noticed, by an expert, relying upon .the sensitiveness of his fin er tips to the pulse activity of the wrist. T e rehability of such an observation is of course doubtful at an time, but even this is not obtainable, un er ordinary circumstances, unless the expert, whether doctor or nurse, is preson the other hand, can be used by the patient" himself if necessary, and if applied y either the patient or a nurse at given intervals throughout the day. it will roduce arecord of the heart .action that Wlll be invaluable to the attending physician when he calls upon the patient.

In the accompanying drawings:

' Fig. 1 is an enlarged elevation of the device, as seen from the left in Fig 2, but with the cover plate removed.

Fig. 2 is a side elevation, as seen from the 1927. Serial No. 209,385.

right in Fig. 1, of the interior mechanism, but showmg the outer casing in central, vertical section.

Referring to the drawings more particularly and by reference characters, 3 designates a cylindrical casing having end doors 4 and 5, which are preferably hin ed as at 6, so that the doors or covers can s conveniently opened when access-to the mechanisms is desired. The casing 3 isfurther provided with an integral centrally dependin leg 7, and a pair of laterally spaced brac ets or legs 8 and 9 at the sides of the leg 7. The legs 8 and 9 have socket members 10 for receiving the middle sections of two adjahent fingers securin such finger sections in the sockets. It will e understood that when the fingers are in place they will be bent at right angles, and the finger tips will extend down below the sockets to positions on either side of and below the end of the central bar 7. Thus the device is supported or carried by the hand of the operator and when it is to be used, it is so held that these two finger tips may be employed to locate the most suitable area of the body surface before the mechaof the hand, and straps 11 for firmly nism is started. The leg 7 has a bar 12 sliddistentions in the radial arteries, and which,

in turn, impart the desired fluctuations or vibrations to the rod or bar 12.

The bar 12, in addition to guiding. in the leg 7 guides in a bearing extension 15 of a frame or post 16, which, in turn is integral with and extends centrally up into the casing 3. This bar 12 operates an indicator or marker 18 and an escapement mechanism, which, as a unit is designated by the numeral 19. The marker 18 is carried by the rod 12, and is spring held, as by a spring 22, against a book or series of diagram disks vor sheets 20, which are rotated, in a manner to be described, and which, as the rotate, receive an irregular line of mar s or impressions 21. A second spring 23, has a similar function and also serves to restore the marker to its original or lower position. The escapement 19 comprises a vertically slidable rack bar 24 having a shaft 25 on which is trunnioned an anchor 26 having pulleys 27, 28 whch are operatively associated with a large escapement wheel 29. An arm 30 of the anchor 26 enga es and is operated by the bar 12, so that $01 each pulsation imparted to the head 13, the escapement 19 will permit the wheel 29 (which is spring rotated), to turn the distance between two of its teeth. S rings, such as 31, may be employed to yie dingly hold the escapement bar in its operative position.

The escapement wheel 29, together with a spring case 33, which is secured to it, are rotatably carried on a shaft 34. The shaft 34 is j ournaled, at one end, in a spider like frame 35, fixed in the casing 3, and has its other end terminating and journaled in a two ended hub 36-37 of the frame 16. A spiral spring 38 is contained within the case 33 and has one end secured thereto and the other end to the shaft 34, in a conventional manner, so that when the shaft 34 is turned it will wind up the spring. The shaft 34 is preferably woun by a wing nut 39 which is secured on one end thereof. The shaft is held against reverse rotation by a pawl 40 and a ratchet wheel 41. When the device is not running or operating the wheel 29 is held against rotation b a tooth clutch hub 42 of a disk plate 43 whio is splined onto the hub member 36. The hub 42 co-operates with a similar toothed clutch hub 44 of the wheel 29. The clutch 42, 44 is closed or moved into enga ement by a pin 45, which is slidably carried in the frame 16,

and which is actuated, against the resistance of a spring 46, by a cam or wedge member 47 carried on a second escapement wheel 48. This closing movement of the clutch, which stops all rotation of the wheel 29, also causes the disk plate 43 to actuate a lever 49, throwing the upper end thereof. inward or toward the disk book 20. The upper end of the lever carries a perforator or marker 50, which is thus brought into engagement with and marks the face of the inner disk. Such a mark indicates the start and end of the operating cycle, and, as will soon be described, provides the means for recording the frequency of the heart beats. The lever 49, which is pivotally carried by the wheel 29, as at 51, is held in its inoperative position, during the recording cycle, by suitable means, such as a spring 52, which also disengages the clutch hub 42 when the pin 45 is free from the action of the cam 47. The pointer or marker 50 has a square shank 53, which is normally and non-rot tably at rest in a square socket 54 at the upper end of the lever 49. The

' the marker 50 to pass the lower end of the frame 16 when the wheel 29 is rotated. Th as the wheel is about to com late a hai revolution from the position s own in the drawing, rear end projection or fin er 57 engages a cam bracket 58, secured in the lower part of the casing 3, and thus slides the squared shank 53 from the socket 54, and as the wheel continues to turn the long end of the pointer stops against the frame post 16, causlng it to swing behind, but as soon as the marker is clear of the post, the spring 55 will restore the parts to t 0 initial position, as shown. A

The esca ment wheel 48 is secured to and rotates wit a spring case 59, which, in turn, is a secured on a shaft 60, rotatably carried in the hub member 37. The spring 61, within the case 59, is also of the spiral type, and has its outer end secured to the case while its inner end is anchored to a projection 62 of the hub 37. The outer end of the shaft is threaded to receive a wing nut 63, which may serve the double purpose of clam in the chart disks 20 in a solid book, an o winding) up the spring 61. A plate 64 is prefera ly interposed between the nut 63 and the book 20, so as to 've rigidity to the charts and to serve as an e ective clampin member in conjunction with the case 59. The charts themselves may be of any desired material, but are preferably made of fairly heavy paper, and each is provided, adjacent to its edge, with an annular series of equally spaced members, as shown at 65 in Fig. 1. Immediately within the circle of ti 'res 65, I print two lines 66, which define t espace within which the pulse is to be recorded. It may here be noted that the shaft 60 carries a ratchet wheel 67, which operates against a dog 68, on the hub 37, and thus permits rotation of the members 48, 59, 20, 64 in one direction only.

It is necessary to have the disks 20 rotate at a certain predetermined speed, preferably one revolution per minute, and this is accomplished by a time controlled escapement mechanism, generally designated by the numeral 69. This escapement consists of a .shaft 70, carried in a rack bar 71, a balance Wheel 72, rotatable on the shaft and having a pinion 73 engaging a toothed segmental rack 74 of a shaft 75 journaled in a bracket 76 carried on the shaft 70. The shaft 75 is further provided with an escapement lever 77, having pulleys 78 for oscillating, intermittent engagement with the teeth of the wheel 48. The fiy wheel 72 is provided with a hair spring 79, and governs the speed of the wheel 48 in the same conventional manner as in a watch or clock movement.

The rack bar 71 is slidably mounted in bearings 80, on the post 16, and, at its lower end, extends through the casing 3, terminating in a button 81, and intermediate the button 81- and the casing is a spring 82 which tends to hold the bar 71 down, with the escapement 69 in its operative position with respect to the wheel 48.

The rack bar 71 has a toothed section, which engages one side of a fixed pinion 83, while at the other side the pinion is engaged by a similar section of the rack bar 24, which is also slidable, vertically, and carries the escapement 19. It will thus be seen that the wheels 29 and 48 may readily be released from the respective escapements 19 and 69 by merely pushing the button 81 upwardly. To

prevent the spinning or unwinding of the wheels 29 and 48, however, and to stop them at a convenient starting point, for the next pulse test, I provide them with a pair of lugs 84 and 85, respectively, which stop against the ends of a cross bar 86, which is vertically movable, so that the lugs 84--85 can be released, and is carried on a rod 87 which extends down through the leg 7 to a point im-' mediately above the button 13. This rod 87 is normally held down by a spring 88, but may easily be moved up, so as to free the lugs 84, 85, and thus start the recording process, by a little extra upper pressure on the button 13.

With the various arts of the device in the positions shown in ig. 1, and with the casing mounted on two fingers, as previously described, the recording rocess is efi'ected as follows: After the deslred arterial location is found, and the button 13 placed upon it, the device is pressed down until the rod 87 trips the lugs 84 and 85. The pressure is then relieved to the required extent so that the rod 12 will be made sensitive to the pulse action. The charts 20 immediately start to rotate at a predetermined speed, it being understood that the springs 38 and 61 have first been wound up, and as the clutch members 42 and 44 are not closed, the wheel 29 is also free to rotate as fast as the escapement 19 will permit. As the speed of rotation of the wheel 29 is dependent entirely upon the frequency of the heart beats, whereas, the'speed of the charts is time controlled, it will be seen that the speed of one may be faster or slower than the other. Consequently the location of the needle or marker 50, at the end of the cycle or complete rotation of the charts, will be governed entirely by the number of heart beats per minute. And if the marker 50 is, when started, at 1 (of the figures it will, at the end of the cycle, be opposite the number which would indicate the number of heart beats recorded during the minute. As the minute test is terminated the cam 47 engages the rod 45, thus closing the clutch 42 and stopping the wheel 29. v This same movement, acting through the lever 49, also causes the marker 50 to be brought into engagement with the face of the chart. If the marker is a en or pencil a mark will result, or if a need e, a perforation will be made adjacent to the number, and thus give a permanent record of the pulse frequency.

During the course of the revolution, 'ust noted, the marker 18 has also been functioning, and has imprinted or impressed the chart with an irregular saw tooth, line 21, or rather with a continuous series of short lines, each two of which have been recorded in response to the pulse beats. The length and condition, as well as the relative closeness of the lines to each other, indicate various pulse characteristics. Thus, long lines would indicate a heavy or strong heart action, while shorter lines would indicate a weaker (though not necessarily slower) heart action, and possibly a lower blood pressure.

Theangle of the pulse line (i. e. the up line as distinguished from the return stroke) with respect to the radial line of the chart would indicate the intensity or acuteness of the heart action. And if some of the lines are closer than others, there would be furnished a reliable record that the heart is more or less spasmodic in its action and functions faster at certain intervals during the minute test. Thus it will be seen that all of the essential characteristics of the heart action are permanently recorded, and the value of such a record, to a physician, skilled in reading it, becomes inestimable.

lVhen the wheel 48 has made one complete minute revolution, the lug 85 stops 'against the bar86 and the recording process ceases. The graphed or marked chart is then removed, leaving the next one in position for the next test. The button 81 is then pushed up, freeing the escapement 19, thus permitting the wheel 29-to rotate with the marker 50 to its initial position, where it is stopped by the lug 84 meeting the cross bar 86. Similarly the esca ement 69 is freed from the wheel 48 so that if the latter has not completed its full revolution it may then do so.

It is understood that suitable modifications may be made in the general design and structural details of the invention as herein shown, provided, however, that said modificatidps come within the spirit and scope of the appended claims. Having now there-- tion, what I claim to be new and desire to protect by Letters Patent is:

1. A sphygmograph comprising a circular chart having a progressive series of numbers adjacent its outer edge, a marker movable in a path adjacent to said series of numbers, but normally out of contact with the chart, time control ed means for rotating the chart with respect to the marker, an exposed vibrator for contact with the body surface so, as to be sensitive to arterial distentions, and

. means, responsively associated with the vibrator, for causing the marker to engage the chart, at a predetermined time interval, -'whereby a mark will be described upon the chart adjacent to a number of the series which will correspond to the pulse frequency.

2. A sphygmograph comprising a housing, a recording mechanism Wit in the housing, a vibrator rod extending from the housing with its inner end operatively associated with the recording mechanism and with its outer end adapted to be applied to a body surface for in reading conjunction with said series of numbers.

6. A sphygmograph comprising a rotat able chart having an annular series of numbers thereon, means for rotating the chart at a predetermined speed, a vibrator mounted for sliding action in a radial direction with respect to the chart and having its outer end exposed for body contact, a marker carried by theinner end of the vibrator for constant marking contact with the chart, and a second marker mounted for rotation on an axis coincident with that of the chart for intermittent marking contact with the chart, means for rotating the second marker, and an escapement mechanism controlled by the vibrator, forcontrolling the rotary movement of the second marker.

7. A sphygmograph com rising a circular chart, means for rotating t e chart at a predetermined speed, a vibrator havinga marker for contact with the chart as the latter rotates, a second marker, normally out of engagement with the chart, but rotatable on an axis concentric with that of the chart, means for rotating the second marker, means associated with the vibrator for controlling the speed of the second marker, and means operaj tive upon a predetermined movement of the chart for moving the second marker into marking engagement with the chart.

In testimon whereof I aflix my signature.

NDREAN G. RONNING.

responsive action to arterial distentions, and

a pair of clampin devices, arranged at opposite sides of the vibrator rod for engagement with two fingers of the operators hand.

4. A sphygmograph comprising a recording mechanism having a vibrator rod extending therefrom for application to the body surface so as to be responsive to arterial dis-- tentions, and which will transmit vibrations thus imparted to it to the recording mechanism, said recording mechanism bein spring operated but normally inactive, an means rendered operative by an inward movement of the rod that is greater than that to which it is subject when normally transmitting impulses, to release the recording mechanism from its inactive condition.

5. A sphygmograph'comprising a rotatable chart having an annular series of numbers thereon, means for rotating the chart at a predetermined speed, a vibrator mounted for sliding action in a radial direction with respect to the chart and having its outer end exposed for body contact, a marker carried by the inner end of the vibrator for constant marking contact with the chart, and a second marker mounted for rotation on an axis coincident with that ofthe chart for intermittent marking contact with the chart, and

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